It is not serious, :\ especially with my knowledge in programming I not far have left in modernization YaPB, and if it is honour, now YaPB at all does not work (badloadf)
Btw I here have found in source sdk NavMesh algorithm, but anything there in earnest has not understood
(I approximately present as it works - runs bot on a map and yet he runs and there where he has run the navigating zone is created - IMHO)
Here function CNavMesh::BeginGeneration() in a nav_generate.cpp file begins the generation process..., and CNavMesh::UpdateGeneration() executes it while generation isn't complete.